BMN-333

Ascendis Pharma of Denmark has gained its third FDA new drug approval in the last six years as the U.S. regulator has signed off on Yuviwel as a treatment for achondroplasia. Ascendis Pharma is spiraling upward by way of its TransCon platform. For the third time in six years, the Copenhagen-based biopharma has scored an FDA approval for a rare disease medicine that was developed with its “transient conjugation” drug delivery technology. The U.S. regulator has signed off on Yuviwel, a once-weekly injection to treat children with achondroplasia, a rare genetic disorder that causes dwarfism. The accelerated approval covers children age 2 and older who have open growth plates, which are areas where cartilage develops at the end of bones, allowing them to lengthen.By providing continuous exposure to C-type natriuretic peptide (CNP) receptors, Yuviwel can counter the effects of the fibroblast growth factor receptor 3 (FGFR3) gene, which causes the protein to become overactive and restrict growth. This continuous systemic exposure to CNP over the weekly dosing interval sets Yuviwel apart in the achondroplasia treatment landscape, according to Ascendis.“The approval of once-weekly Yuviwel is a major step forward in the treatment of children with achondroplasia, giving physicians for the first time the option of prescribing a once-weekly medicine backed by compelling efficacy and excellent tolerability data from three randomized, double-blind, placebo-controlled clinical trials,” Carlos Bacino, M.D., of Baylor University and Texas Children’s Hospital, said in a release.The three trials and up to three years of open-label extension data demonstrated the ability of Yuviwel to provide improvements in annualized growth velocity versus placebo.Achondroplasia is the most common form of short-limbed dwarfism, affecting between 1 in 10,000 and 1 in 30,000 live births and preventing adults from growing taller than four feet,10 inches. The condition can increase the likelihood of spinal cord compression and respiratory blockages early in life along with other muscular and neurological problems.The company said it expects to make Yuviwel available early in the second quarter of this year. In a conference call Monday morning, Ascendis said it will reveal the price in the coming days.The nod comes with a valuable pediatric disease priority review voucher, which can be used to speed the review of a future drug application."Most of the products we're developing are getting priority review, so I'm not sure that we actually need to keep it. I think we'll sell it," Scott Smith, Ascendis' chief financial officer, said in a lighter moment during the conference call.Yuviwel’s approval comes after the FDA delayed its decision on the medicine by three months back in November. Ascendis will compete with BioMarin in the indication. The California company gained approval for its CNP treatment Voxzogo in 2021. The daily injected medicine generated sales of $927 million last year, which were up 26% and accounted for 29% of the company’s revenue in 2025.BioMarin is working on a longer-acting version of Voxzogo, BMN 333, which has shown promise in a phase 1 trial and could be launched by 2030, the company has said. BMN 333 has shown area-under-the-curve (AUC) levels greater than three times those observed in other long-acting CNP studies, BioMarin said in August of last year, referring to Ascendis’ trials for Yuviwel. AUC is a pharmacokinetic measure indicating the total exposure to a drug over time.Ascendis’ current advantage with Yuviwel is its consistent, sustained release over its weekly dosing as opposed to Voxzogo’s daily administration.Last month, BridgeBio revealed the success of a phase 3 trial of its FGFR1-3 selective tyrosine kinase inhibitor infigratinib in children with achondroplasia. BridgeBio and its partner Kyowa Kirin plan to apply for approval of infigratinib in the second half of this year.Ascendis used its TransCon technology to develop Skytrofa, a long-acting growth hormone for children which was approved in the U.S. in 2021, and Yorvipath, a hormone replacement therapy for hypoparathyroidism, which scored an FDA nod in 2024.  Sales for Skytrofa reached 206 million euros ($242 million) last year, which were up 5% year over year. Yorvipath generated sales of 477 million euros ($561 million) last year, with 187 million euros ($220 million) coming in the fourth quarter."We expects Yuviwel revenue to be light this year but don't think that reflects on long-term value," analysts from ISI Evercore wrote in a note to investors. "We continue to believe our $1 billion CNP franchise peak is quite conservative."Evercore sees more sales potential for Yuviwel in Europe than in the U.S., citing sales results for Voxzogo. There are also other potential indications for the treatment. The company also is exploring the potential of Yuviwel in combination with other treatments.